Geography - Theses, Dissertations, and other Required Graduate Degree Essays

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Influences on Hyporheic Exchange in a Small Coastal British Columbia Suburban Stream

Date created: 
2013-03-28
Abstract: 

This study examined how discharge, streambed topography, and channel planform influence hyporheic exchange in a coastal suburban stream in B.C. Tracer experiments were carried out in four reaches of Hoy Creek in Coquitlam using sodium chloride, and piezometers were installed to determine the vertical hydraulic gradient (VHG). The tracer data were used in OTIS, a transient storage model, to determine the following parameters: cross-sectional area of the stream and storage zone, dispersion, and the storage zone exchange coefficient (α). For the lower reaches, there was no significant relation between α and discharge; however, there was a significant positive relation between α and discharge for the upper reaches. Dispersion and the cross-sectional area of the storage zone did not change with discharge. VHG and streambed tracer breakthrough curves/data showed predominantly upwelling conditions. Hyporheic flow occurred mainly through meander bends, step-pool systems, and riffles.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Ilja van Meerveld
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

Bogs and their laggs in coastal British Columbia, Canada: Characteristics of topography, depth to water table, hydrochemistry, peat properties, and vegetation at the bog margin

Author: 
Date created: 
2013-03-28
Abstract: 

The transition zone at the margin of raised bogs (the lagg) is rarely studied, yet it can be important for maintaining a high water table in the peat mound. Where the lagg has been damaged or lost to agriculture, industry, or residential development, it may be necessary to restore a functional lagg inside the historic bog boundary to maintain the ecological health of the bog. Seventeen laggs from raised bogs in coastal British Columbia (BC) were studied to determine the natural range of lagg characteristics in this region. The laggs could be separated into two hydrotopographic forms: Marginal Depression (with mean early summer depth to water table of 12 cm and mean tree basal area of 2.8 m2/ha) and Flat Transition to forest (with mean early summer depth to water table of 34 cm and mean tree basal area of 26.3 m2/ha). These hydrotopographic forms were further classified into four vegetative lagg types: 1) Spiraea Thicket, 2) Carex Fen, 3) Peaty Forest, and 4) Direct Transition to forest (no lagg ecotone). The Carex Fen and Direct Transition lagg types were generally found in the Pacific Oceanic wetland region (cool, wet climate), while the Spiraea Thicket and Peaty Forest lagg types were more common in the Pacific Temperate wetland region (relatively warmer and drier climate). Regional differences in bog and lagg characteristics appear to be related to mean annual precipitation and mean annual temperature. The timing of seasonal fluctuations in depth to water table were similar for bogs and laggs, but the amplitude was generally greater in the lagg. Near-surface pore-water chemistry varied across the bog expanse – bog margin transition: pH, Ca2+ concentrations, and pH-corrected electrical conductivity generally increased from bog to lagg, although not consistently for individual study transects. Mg2+ and Na+ concentrations increased from bog to lagg for less than half of the studied transects. The most consistent indicators of the lagg, which may be of greatest use for delineation of lagg conservation zones include: topography, depth to water table, tree basal area, ash content of the peat, and dominant species.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Ilja van Meerveld
Department: 
Environment: Department of Geography
Thesis type: 
(Dissertation) Ph.D.

Spatial-temporal epidemiology of violent trauma in urban environments

Date created: 
2013-03-27
Abstract: 

The World Health Organization has declared violence to be a significant public health problem (2002). This thesis uses a spatial epidemiology approach to investigate clusters of violent injury in the Metro Vancouver area.Trauma registry data were analysed using a visually-enhanced ranking method in geographic information systems to identify violent injury hotspots. The identified hotspots were then examined using environmental, spatial-temporal, victim, and deprivation variables. Data from hotspot observations, victim and incident records, and the use of a Vancouver-specific deprivation index were included.Alcohol availability, time of day, and social deprivation are several of the factors found to be strongly related to violent injury hotspots. However, the hotspots were found to occur in several disparate geographical contexts, each of which is characterised to produce a series of multidimensional profiles of urban spaces of violent injury. To conclude, the emergence of a non-statistical, exploratory paradigm in geographic information science is promoted.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Nadine Schuurman
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

Low-flow hydraulic geometry of small, steep streams in southwest British Columbia

Date created: 
2005
Abstract: 

This investigation explores the closely related ideas of low-flow at-a-station hydraulic geometry and resistance to flow of small, steep mountain streams. Thirteen reaches in five tributaries of Chilliwack River, British Columbia are examined. The data suggest that power functions well describe the relationships. Changes in the mean cross-section velocity account for the majority of the changing discharge; 31 of the 61 cross-sections have velocity exponents that are greater than the water-surface width and mean-depth exponents combined. The hydraulic geometry is highly variable between cross-sections in a reach, between reaches, and between streams. Resistance to flow in these mountainous settings is high and strongly dependent on stage. In the data, Darcy-Weisbach resistance factor varies over five orders of magnitude and Manning's n varies over three orders of magnitude. Despite this extreme range, both the power equations (at a cross-section) and Keulegan equation (for reach-averaged values) well describe the relationships.

Document type: 
Thesis
File(s): 
Department: 
Department of Geography - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Hidden champions of the B.C. forest industry: Are small firms at the cutting edge of value chain innovation?

Date created: 
2005
Abstract: 

British Columbia's once formidable commodity based forest industry has undergone profound economic restructuring. "Value-added" (secondary) manufacturing is a key component of contemporary production, and is widely recommended in theory and industrial strategy for achieving higher value and overcoming high costs and wood fibre constraints. High value production anticipates the role of small and medium sized enterprises (SMEs) operating within flexibly specialized networks. My thesis addresses this promise. An extended case study research methodology underpins this investigation of local development, growth and networking strategies of 14 BC firms. Conceptually, the research integrates flexible specialization and value chain literatures within the specific contingencies of forest resource production. The results indicate that advanced networking and communication synergies anchor firms to the home milieu and connect them to export markets. Flexible specialization production shows potential in the current restructuring of BC's forest economy. Yet, the long-term prospects for sustaining valueadded production remain unclear.

Document type: 
Thesis
File(s): 
Department: 
Department of Geography - Simon Fraser University
Thesis type: 
Thesis (M.A.)

Measurement of physical and hydraulic properties of organic soil using computed tomographic imagery

Date created: 
2005
Abstract: 

Defining and measuring the physical properties of peat is difficult but essential in order to accurately model the flux and storage of water in peatlands. The goal of this research is to develop a method to measure the physical and hydraulic properties of organic soil using computed tomographic imagery. Specifically, this research seeks to determine if two and three-dimensional images of peat, produced using a MicroCT scanner, can be used to accurately characterize air-filled porosity, active porosity, pore size distribution, pore saturated area and capillary films of porous Sphagnum cells at different soil tensions. Unsaturated hydraulic conductivity at similar soil tensions was also determined. Results indicate that the proportion of small air-filled pores in the peat sub-samples increased with increasing depth and unsaturated hydraulic conductivity was greater at deeper depths than shallower depths at equivalent soil tensions, suggesting this method is a potentially valuable tool for measuring peat properties.

Document type: 
Thesis
File(s): 
Department: 
Department of Geography - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Geographies of immigrants at risk for homelessness in Greater Vancouver

Date created: 
2006
Abstract: 

This research introduces methods and results that explore geographies of immigrants at-risk for homelessness. Recent immigrants, in particular, are identified as a group at elevated risk of homelessness. The research draws on a range of data sources of varying resolution including CMHC housing indicators, census data and a postal survey, to illustrate how census-based socioeconomic GIs can be improved by using highresolution data augmented with complementary primary data. Three findings are highlighted: 1) recent immigrants at-risk for homelessness-especially those spatially concentrated-are disproportionately located in Vancouver's inner suburbs (Barnaby and Richmond); 2) while the majority of recent immigrants at-risk are located in at-risk areas, a sizeable minority are dispersed in areas that are otherwise well-housed; and 3) risk of homelessness is often highly localized and misrepresented by coarsely aggregated census data.

Document type: 
Thesis
File(s): 
Department: 
Department of Geography - Simon Fraser University
Thesis type: 
Thesis (M.A.)

Runoff generation mechanisms in a steep first-order British Columbian watershed.

Author: 
Date created: 
2010
Abstract: 

This research was undertaken in the Malcolm Knapp Research Forest in British Columbia Canada and aimed to examine runoff generation mechanisms in a steep forested watershed. The research questions were: (1) can water infiltrate into the bedrock in the study watershed, (2) can bedrock infiltration be described with simple infiltration models that have been developed for soil infiltration, and (3) what is the spatial variation in the relations between discharge and piezometric response on the hillslope? To answer these questions hydrometric data from a 20 m by 18 m hillslope and from bedrock infiltration ponds were collected. The results from this research showed that the bedrock is permeable and that soil infiltration models can represent bedrock infiltration. The hillslope has two distinct water table zones; a hillslope zone and riparian zone. The riparian zone is located 0-8 m from the stream while the hillslope zone is 8-18 m uphill.

Document type: 
Thesis
File(s): 
Senior supervisor: 
I
Department: 
Department of Geography - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Exploring the characterization of uncertainty in census and borehole data using rough sets

Author: 
Date created: 
2005
Abstract: 

This research introduces rough sets to better characterizing spatial relationships and uncertainty in two examples. First, scale issues in census data are addressed. Census data provide demographic and socio-economic information at specific area units. Hence, derived spatial information are scale-dependent leading to uncertainty when analyzing results at different scales. Rough sets mitigate scale distortions and provide scale-sensitivity measure during scale transition. It employs the metaphor of topology to illustrate the ability of rough sets to retain spatial relationships of adjacency and contiguity. Second, rough sets and transition probability are used to characterize sediment distribution. The study simulates sediment state and transitions for low and high quality borehole data by providing better geological understanding. It also assesses Geological Survey of Canada standardization scheme for classifying borehole data. The utility of rough sets is demonstrated as a knowledge base tool for characterizing uncertainty irrespective of the data under study.

Document type: 
Thesis
File(s): 
Department: 
Department of Geography - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

The way of rights and the right of way: panhandling and rights in public space

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009
Abstract: 

There is a tradition within geography of calls for inclusivity gained by the “cry-and-demand” by marginalized people to claim rights in and to public space. However, the utility of rights as a tool for gaining social justice bears closer inspection. Using as an example debates around the Safe Streets Act in British Columbia, I interview panhandlers to test the convergence between their lived-experiences and the dominant rights-discourse used in debates around the law. This reveals a gap between the reality of being marginalized on the street, and dominant rights-based narratives. Furthermore, panhandlers question whether they can assert even the limited forms of rights available to them. I suggest that the problem is deeply inherent in rights themselves: specifically, in a strong liberal-ontology present in rights-discourse, which views individuals as isolated monads and limits discussion of alternative strategies for social justice while masking the everyday realities of oppression.

Document type: 
Thesis
File(s): 
Senior supervisor: 
N
Department: 
Dept. of Geography - Simon Fraser University
Thesis type: 
Thesis (M.A.)